1. Field of the Invention
The invention relates to a magnetic head device comprising a magnetic head for magnetically recording information on and/or reproducing information from a magnetic tape, and tape guides, each for restricting a running position of the magnetic tape and, more particularly, to a magnetic head device in which there is no need to perform an azimuth adjustment when a magnetic head device is assembled into a mechanism portion of a magnetic recording and reproducing apparatus.
2. Related Background Art
Hitherto, a magnetic head device in which there is no need to perform an azimuth adjustment when the magnetic head device is assembled into a mechanism portion of an apparatus such as a cassette tape recorder or the like has been proposed in U.S. Pat. No. 5,202,808.
FIG. 4 is a perspective view showing a magnetic head device to which the technique disclosed in the above-noted patent is applied.
The magnetic head device is used for a cassette tape recorder and is constructed by a magnetic head 101 and a guide unit 102. The guide unit 102 is constructed by integrally forming a first pair of tape guides 103 which are arranged so as to be adjacent to the side surfaces on both sides in the running direction of a magnetic tape and a second pair of tape guides 104 which are arranged on the outside of the tape guides 103. The magnetic head 101 is fitted and fixed into an opening portion 102a formed in the center portion of the guide unit 102 in the magnetic tape running direction. The tape guides 103 are inserted into a head inserting opening portion 200 of a cassette half together with the magnetic head 101 upon recording or reproduction. The tape guides 104 are inserted into right and left small windows 210 of the cassette half.
In the above construction, when the magnetic head 101 and guide unit 102 are fixed before assembling into the cassette tape recorder, the guide unit 102 is previously positioned. A magnetic tape 105 is run along two arm-shaped guide portions 103a and 104a of the tape guides 103 and 104. An azimuth of the magnetic head 101 is adjusted in accordance with an azimuth adjustment signal of the magnetic tape, thereby positioning the magnetic head 101 and fixing the magnetic head to the guide unit 102 by an adhesive agent. Thus, an azimuth adjustment when assembling the above component elements into a mechanism portion of the tape recorder is unnecessary.
In the above conventional technique, however, since the four tape guides are integratedly formed as a guide unit 102, dimensional precisions at four positions have to be fairly severely set and it is very difficult to manufacture the guide unit. Specifically speaking, hitherto, such a kind of guide unit is made of plastic and there is a concern that of a dimensional variation will occur with every molding lot. It is, therefore, difficult that a straightness at a relative position of the four guides, which exert an influence on a running stability of a tape, are accurately held constant. When the precision of the straightness is low, an edge of the magnetic tape which runs along the four tape guides comes into contact with the guide portions of the tape guides, so that curling of or damage to the tape occurs.
Since the magnetic head 101 is assembled into the guide unit 102 in which the four guides are integrally formed, a total width dimension L in the tape running direction of the magnetic head 101 and tape guides 103 which enter the head inserting opening portion 200 of the cassette half is large. Particularly, when the guide unit 102 is made of plastic, a certain degree of thickness is needed for the tape guides 103 and there is a tendency such that the width dimension L increases. Therefore, when the magnetic head 101 and tape guides 103 are inserted into the head inserting opening portion 200 of the cassette half, there is a concern that a problem will occur such that the guides 103 collide with the edges of the opening portion 200 and cannot be inserted.